/*
    Copyright (c) 2005-2020 Intel Corporation

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/
#include "common/test.h"
#include "common/concurrency_tracker.h"
#include "common/spin_barrier.h"
#include "common/utils.h"
#include "common/utils_concurrency_limit.h"

#include "oneapi/tbb/global_control.h"
#include "oneapi/tbb/parallel_for.h"

#include <limits.h>
#include <thread>

//! \file conformance_global_control.cpp
//! \brief Test for [sched.global_control] specification

const std::size_t MB = 1024*1024;
const double BARRIER_TIMEOUT = 10.;

void TestStackSizeSimpleControl() {
    oneapi::tbb::global_control s0(oneapi::tbb::global_control::thread_stack_size, 1*MB);

    {
        oneapi::tbb::global_control s1(oneapi::tbb::global_control::thread_stack_size, 8*MB);

        CHECK(8*MB == oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::thread_stack_size));
    }
    CHECK(1*MB == oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::thread_stack_size));
}

struct StackSizeRun : utils::NoAssign {

    int num_threads;
    utils::SpinBarrier *barr1, *barr2;

    StackSizeRun(int threads, utils::SpinBarrier *b1, utils::SpinBarrier *b2) :
        num_threads(threads), barr1(b1), barr2(b2) {}
    void operator()( int id ) const {
        oneapi::tbb::global_control s1(oneapi::tbb::global_control::thread_stack_size, (1+id)*MB);

        barr1->timedWaitNoError(BARRIER_TIMEOUT);

        REQUIRE(num_threads*MB == oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::thread_stack_size));
        barr2->timedWaitNoError(BARRIER_TIMEOUT);
    }
};

void TestStackSizeThreadsControl() {
    int threads = 4;
    utils::SpinBarrier barr1(threads), barr2(threads);
    utils::NativeParallelFor( threads, StackSizeRun(threads, &barr1, &barr2) );
}

void RunWorkersLimited(size_t parallelism, bool wait)
{
    oneapi::tbb::global_control s(oneapi::tbb::global_control::max_allowed_parallelism, parallelism);
    // try both configuration with already sleeping workers and with not yet sleeping
    if (wait)
        utils::Sleep(100);
    const std::size_t expected_threads = (utils::get_platform_max_threads()==1)? 1 : parallelism;
    utils::ExactConcurrencyLevel::check(expected_threads);
}

void TestWorkersConstraints()
{
    const size_t max_parallelism =
        oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::max_allowed_parallelism);
    if (max_parallelism > 3) {
        oneapi::tbb::global_control c(oneapi::tbb::global_control::max_allowed_parallelism, max_parallelism-1);
        CHECK_MESSAGE(max_parallelism-1 ==
               oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::max_allowed_parallelism),
               "Allowed parallelism must be decreasable.");
        oneapi::tbb::global_control c1(oneapi::tbb::global_control::max_allowed_parallelism, max_parallelism-2);
        CHECK_MESSAGE(max_parallelism-2 ==
               oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::max_allowed_parallelism),
               "Allowed parallelism must be decreasable.");
    }
    const size_t limit_par = utils::min(max_parallelism, 4U);
    // check that constrains are really met
    for (int wait=0; wait<2; wait++) {
        for (size_t num=2; num<limit_par; num++)
            RunWorkersLimited(num, wait==1);
        for (size_t num=limit_par; num>1; num--)
            RunWorkersLimited(num, wait==1);
    }
}

void RunParallelWork() {
    const int LOOP_ITERS = 10*1000;
    oneapi::tbb::parallel_for(0, LOOP_ITERS, [](int){ utils::Sleep(1); }, oneapi::tbb::simple_partitioner());
}

struct SetUseRun: utils::NoAssign {
    utils::SpinBarrier &barr;

    SetUseRun(utils::SpinBarrier& b) : barr(b) {}
    void operator()( int id ) const {
        if (id == 0) {
            for (int i=0; i<10; i++) {
                RunParallelWork();
                barr.timedWaitNoError(BARRIER_TIMEOUT);
            }
        } else {
            for (int i=0; i<10; i++) {
                oneapi::tbb::global_control c(oneapi::tbb::global_control::max_allowed_parallelism, 8);
                barr.timedWaitNoError(BARRIER_TIMEOUT);
            }
        }
    }
};

void TestConcurrentSetUseConcurrency()
{
    utils::SpinBarrier barr(2);
    NativeParallelFor( 2, SetUseRun(barr) );
}

// check number of workers after autoinitialization
void TestAutoInit()
{
    const size_t max_parallelism =
        oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::max_allowed_parallelism);
    const unsigned expected_threads = utils::get_platform_max_threads()==1?
        1 : (unsigned)max_parallelism;
    utils::ExactConcurrencyLevel::check(expected_threads);
    CHECK_MESSAGE(oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::max_allowed_parallelism)
           == max_parallelism, "max_allowed_parallelism must not be changed after auto init");
    if (max_parallelism > 2) {
        // after autoinit it's possible to decrease workers number
        oneapi::tbb::global_control s(oneapi::tbb::global_control::max_allowed_parallelism, max_parallelism-1);
        utils::ExactConcurrencyLevel::check(max_parallelism-1);
    }
}

class TestMultipleControlsRun {
    utils::SpinBarrier &barrier;
public:
    TestMultipleControlsRun(utils::SpinBarrier& b) : barrier(b) {}
    void operator()( int id ) const {
        barrier.wait();
        if (id) {
            {
                oneapi::tbb::global_control c(oneapi::tbb::global_control::max_allowed_parallelism, 1);
                utils::ExactConcurrencyLevel::check(1);
                barrier.wait();
            }
            utils::ExactConcurrencyLevel::check(1);
            barrier.wait();
            {
                oneapi::tbb::global_control c(oneapi::tbb::global_control::max_allowed_parallelism, 2);
                utils::ExactConcurrencyLevel::check(1);
                barrier.wait();
                utils::ExactConcurrencyLevel::check(2);
                barrier.wait();
            }
        } else {
            {
                utils::ExactConcurrencyLevel::check(1);
                oneapi::tbb::global_control c(oneapi::tbb::global_control::max_allowed_parallelism, 1);
                barrier.wait();
                utils::ExactConcurrencyLevel::check(1);
                barrier.wait();
                utils::ExactConcurrencyLevel::check(1);
                barrier.wait();
            }
            utils::ExactConcurrencyLevel::check(2);
            barrier.wait();
        }
    }
};

// test that global controls from different thread with overlapping lifetime
// still keep parallelism under control
void TestMultipleControls()
{
    utils::SpinBarrier barrier(2);
    utils::NativeParallelFor( 2, TestMultipleControlsRun(barrier) );
}

#if !(__TBB_WIN8UI_SUPPORT && (_WIN32_WINNT < 0x0A00))
//! Testing setting stack size
//! \brief \ref interface \ref requirement
TEST_CASE("setting stack size") {
    std::size_t default_ss = oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::thread_stack_size);
    CHECK(default_ss > 0);
    TestStackSizeSimpleControl();
    TestStackSizeThreadsControl();
    CHECK(default_ss == oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::thread_stack_size));
}
#endif

//! Testing setting max number of threads
//! \brief \ref interface \ref requirement
TEST_CASE("setting max number of threads") {
    TestWorkersConstraints();
    TestConcurrentSetUseConcurrency();
    TestAutoInit();
}

//! Test terminate_on_exception default value
//! \brief \ref interface \ref requirement
TEST_CASE("terminate_on_exception: default") {
    std::size_t default_toe = oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::terminate_on_exception);
    CHECK(default_toe == 0);
}

//! Test terminate_on_exception in a nested case
//! \brief \ref interface \ref requirement
TEST_CASE("terminate_on_exception: nested") {
    oneapi::tbb::global_control* c0;
    {
        oneapi::tbb::global_control c1(oneapi::tbb::global_control::terminate_on_exception, 1);
        CHECK(oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::terminate_on_exception) == 1);
        {
            oneapi::tbb::global_control c2(oneapi::tbb::global_control::terminate_on_exception, 0);
            CHECK(oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::terminate_on_exception) == 1);
        }
        CHECK(oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::terminate_on_exception) == 1);
        c0 = new oneapi::tbb::global_control(oneapi::tbb::global_control::terminate_on_exception, 0);
    }
    CHECK(oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::terminate_on_exception) == 0);
    delete c0;
}

// The test cannot work correctly with statically linked runtime.
#if !_MSC_VER || defined(_DLL)
#include <csetjmp>

// Overall, the test case is not safe because the dtors might not be called during long jump.
// Therefore, it makes sense to run the test case after all other test cases.
//! Test terminate_on_exception behavior
//! \brief \ref interface \ref requirement
TEST_CASE("terminate_on_exception: enabled") {
    oneapi::tbb::global_control c(oneapi::tbb::global_control::terminate_on_exception, 1);
    static bool terminate_handler_called;
    terminate_handler_called = false;

#if TBB_USE_EXCEPTIONS
    try {
#endif
        static std::jmp_buf buffer;
        std::terminate_handler prev = std::set_terminate([] {
            CHECK(!terminate_handler_called);
            terminate_handler_called = true;
            std::longjmp(buffer, 1);
        });
#if _MSC_VER
#pragma warning(push)
#pragma warning(disable:4611) // interaction between '_setjmp' and C++ object destruction is non - portable
#endif
        SUBCASE("internal exception") {
            if (setjmp(buffer) == 0) {
                oneapi::tbb::parallel_for(0, 1, -1, [](int) {});
                FAIL("Unreachable code");
            }
        }
#if TBB_USE_EXCEPTIONS
        SUBCASE("user exception") {
            if (setjmp(buffer) == 0) {
                oneapi::tbb::parallel_for(0, 1, [](int) {
                    volatile bool suppress_unreachable_code_warning = true;
                    if (suppress_unreachable_code_warning) {
                        throw std::exception();
                    }
                });
                FAIL("Unreachable code");
            }
        }
#endif
#if _MSC_VER
#pragma warning(pop)
#endif
        std::set_terminate(prev);
        terminate_handler_called = true;
#if TBB_USE_EXCEPTIONS
    } catch (...) {
        FAIL("The exception is not expected");
    }
#endif
    CHECK(terminate_handler_called);
}
#endif

//! Testing setting the same value but different objects
//! \brief \ref interface \ref error_guessing
TEST_CASE("setting same value") {
    const std::size_t value = 2;

    oneapi::tbb::global_control* ctl1 = new oneapi::tbb::global_control(oneapi::tbb::global_control::max_allowed_parallelism, value);
    oneapi::tbb::global_control* ctl2 = new oneapi::tbb::global_control(oneapi::tbb::global_control::max_allowed_parallelism, value);

    std::size_t active = oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::max_allowed_parallelism);
    REQUIRE(active == value);
    delete ctl2;

    active = oneapi::tbb::global_control::active_value(oneapi::tbb::global_control::max_allowed_parallelism);
    REQUIRE_MESSAGE(active == value, "Active value should not change, because of value duplication");
    delete ctl1;
}
